Rate this page del.icio.us  Digg slashdot StumbleUpon

The open palette:How to use Inkscape’s new blur filter

by Nicu Buculei

When I was an undergraduate student a few years ago, I was a member of a Linux Users’ Group (LUG) at my college. At this particular college, laptops were a requirement, and most students purchased their laptops directly from the college. At the beginning of each semester, new students would pick up their laptops at designated spots around campus.

Donning Tux t-shirts and wielding posters and install CDs, we LUG members would call out from strategically placed tables to the students picking up their laptops and offer to install Linux on their new laptops right then and there. A decent percentage of the proud new laptop owners were happy to try Linux, if only as a secondary OS.

There was always one particular group of students, however, who resisted. The creatives. They understood why they should run Linux. But they rightfully had doubts about whether they could actually get their school projects done using only Linux. Valid concerns, when you consider at that time:

  • neither sodipodi nor Inkscape (Free and Open Source Software (FOSS) vector illustration tools) development had started
  • the Open Clip Art Library didn’t exist
  • Blender (3D modeling, animation, and rendering software) was not yet open source

A lot of progress has been made in free and open source creative tools since then. If you’ve taken a look at these tools in the past, you may have passed them by just as “the creatives” at the LUG table did. Now is a good time to take another look with us. In this column, we’ll be bringing you articles with tutorials and information on using some of the many FOSS creative tools available now. We’ll also let you know about some of the communities that exist around creating and sharing openly licensed creative content, such as the Open Clip Art Library and Creative Commons’ ccMixter. We hope to inspire you to try out FOSS creative tools and get involved in some of the communities that work to apply the ideas around open source code and collaboration to other forms of creative content.

– Máirín Duffy

The first article in this column showcases a new feature in Inkscape version 0.45, released February 5, 2007: The blur filter.

How to use Inkscape’s new blur filter

The blur filter, one of the most eagerly-awaited Inkscape features, was recently introduced in Inkscape version 0.45. The blur filter opens up a wide range of photo-realistic rendering possibilities. I’ll walk you through some example applications of the blur filter so you can get a feel for what some of those possibilities are. We’ll also touch on some other useful Inkscape tools such as bitmap tracing, inset and outset, and path manipulation. First, though, you’ll need to install Inkscape 0.45.

Installing Inkscape 0.45

Installing Inkscape 0.45 in Fedora Core versions 4, 5, and 6 is quite easy:

yum install -y inkscape

In older versions of Fedora, though, it may be more tricky. To give Inkscape a quick try, you may just want to install an autopackage version of Inkscape with instructions. Be aware, though, that any packages you install via autopackage will not receive updates from yum and as a result may leave your system vulnerable to security attacks.

Please refer to http://inkscape.org/download/ for installation tips for other operating systems.

Now that you’ve hopefully got Inkscape 0.45 installed and ready on your system, let’s get started.

Example 1: Orbs

Orbs such as these have a variety of practical applications. They can be used in creating application icons, web page bullets, web page navigation graphics, and they can even be used in sprites for video games.

Each set of steps below is demonstrated in the screenshots that follow. Fire up Inkscape and follow along.

The base orb

  1. Use the ellipse tool and draw a circle (hold the Ctrl key as you drag the ellipse tool to create a perfect circle).
  2. Fill it with any solid color to your liking (Object > Fill and Stroke, or Shift + Ctrl + F);
  3. Duplicate the circle (Edit > Duplicate or use the Ctrl + D shortcut) and fill the duplicate in with solid black;
  4. Using the gradient tool, change the fill for the duplicate to a radial gradient starting with completely transparent white in the center to partially-transparent black on the border;
  5. Place the center of the radial gradient displaced to the center of the circle. (hint: the Object > Align and Distribute tool will help you align the gradient and circle perfectly.)

screenshot

Texture

  1. Duplicate the circle again (Edit -> Duplicate or Ctrl + D) and fill it with solid white;
  2. Reduce the size of the duplicated circle (Path > Inset, or Ctrl + ();
  3. Draw a random shape using the freehand tool;
  4. Intersect (Path > Intersection, or Ctrl + *) the random shape with the duplicated white circle;
  5. Fill the resulting intersection with a radial gradient going from solid white to completely transparent white;
  6. Blur the path and decrease its opacity (Object > Fill and Stroke).

screenshot

Highlight

  1. Duplicate the circle and fill it with white (Edit -> Duplicate or Ctrl + D);
  2. Duplicate the circle again, fill it with any solid color (we won’t be using this shape in the final artwork), and move it a little to the right and down;
  3. Subtract (select two objects and use Path > Difference, or Ctrl + -) the second duplicate from the first;
  4. Inset the result one step (select and use Path > Inset, or Ctrl + () and then apply blur and reduce the opacity to your liking;
  5. Draw some other random shapes. You can fill them with various colors and gradients, and apply various values for blur and opacity. You’re free to experiment!

screenshot

Darken

  1. Duplicate the circle again (Edit -> Duplicate or Ctrl + D), and give it a black fill this time;
  2. Duplicate it again, give it a white fill, and resize it. (Hint: To resize the circle and preserve its aspect ratio, select it by clicking on it with your mouse, and click and drag on any of the straight corner arrows that appear around it while holding down the Ctrl key. If bent arrows appear, click on the circle itself one more time.) Move this second smaller circle a little to the left and up;
  3. Subtract the second duplicate from the first one (Select both circles and use Path > Difference, or Ctrl + -);
  4. Inset the result just one time (select and use Path > Inset, or Ctrl + ();
  5. Blur and reduce the opacity using the Fill and Stroke dialog (Object > Fill and Stroke).

screenshot

Shadow

  1. Draw an ellipse, put it at the bottom and behind the orb. (Hint: Quickly move objects to the bottom by hitting the End key. You may also use Object > Raise or Lower, Raise to Top, or Lower to Bottom.) Fill the ellipse with black, applying some blur and reducing the opacity.
  2. For a perspective shadow, duplicate the circle, fill it with black, reduce its height, skew it to the right (Object > Transform, ‘Skew‘ Tab), move if needed, place it to the bottom (End key), and apply some blur and reduce the opacity.

screenshot

Variations

  1. Make a few copies of the orb. Select the colored circle (in this case red) and change its color. You instantly get complete orbs with different colors.
  2. It’s possible to even put some content inside the orb: in this case I use a letter made with the text tool, added a highlight, a darken area, and a shadow. Group them (Object > Group, or Ctrl + G), move over the orb and lower their position down the stack. (by hitting the PgUp and PgDn keys) You’ll want to move them above the colored circle but under the various light or dark areas so they appear as if they are inside the orb.

screenshot

Pushing the envelope, put a photo inside the orb:

  1. Import a photo, in this case a head, nicely cut on the contour with GIMP;
  2. Trace (Path > Trace Bitmap) its shape for brightness using a high threshold to get its contour in vector form (see screenshot for example values);
  3. Fill the traced path with a radial gradient going from partially-transparent white to completely transparent black;
  4. Duplicate the traced path, outset it (Path > Outset, or Ctrl + )), fill with black, blur, reduce its opacity, and move it to the bottom (End key);
  5. Group the elements (select all elements to group and hit Ctrl + G), place the group over the orb, and lower its position in the stack (PgDn key).

screenshot

More

The possibilities are infinite; use whatever colors you want and draw the highlights and dark areas according to your own taste.

screenshot

3D Text

Highlight

  1. Using the text tool add some text. I used for this tutorial the word “Orbs”;
  2. Duplicate the text once and duplicate it again and move the second duplicate a little too the right and down. I used different colors to make the screenshot more relevant, you can leave them as is;
  3. Subtract the second duplicate from the first;
  4. Make the resulting shape white, blur it and reduce the opacity to get the highlight effect.

screenshot

  1. Duplicate the text once, duplicate it for a second time, move the second duplicate to the left and up.
  2. Subtract the second duplicate from the first;
  3. Make the result black, blur it and reduce its opacity.

screenshot

Compositions

Base shadow

  1. Import the 3D text and a few orbs. Align them to have the base on the same line ( Object > Align and Distribute);
  2. Draw a black ellipse at the base of the first letter of the text;
  3. Duplicate the black ellipse and move the duplicate under the second letter. Keep Ctrl pressed when moving to keep the movement only on horizontal;
  4. Repeat the step for all objects. As my orbs have a larger body compared with the letters, I used larger ellipses for their shadows;
  5. Unite (Path > Union, or Ctrl + +) all the ellipses, apply some blur and reduce the opacity.

screenshot

Perspective shadow

  1. Duplicate the text and orbs;
  2. Keeping the duplicate selected, ungroup it if you have any groups (Shift + Ctrl + G) and then do a union;
  3. Color the resulted shape in black, reduce its height, skew to the right, move if needed, place it to the bottom;
  4. Apply blur and reduce the opacity.

screenshot

Mirror

  1. Select the text and the orbs, group them;
  2. Duplicate the group and flip it (Object > Flip Vertical, or V), move the flipped group down;
  3. Increase the height of the flipped group and skew it to the left (or to the right if you like that way);
  4. Draw a rectangle over the flipped group and fill it with a gradient starting with solid white and ending with completely transparent white.

screenshot

Example files

All the files produced in this tutorial are available for download:

With contributions from Máirín Duffy.

Máirín Duffy is an interaction designer on the Red Hat Network team. She also contributes to the GNOME and Fedora projects in various design-related capacities. Vices include Battlestar Galactica, Final Fantasy, Hello Kitty, and trying to learn how to speak Japanese.

Nicu Buculei work as a sysadmin and in his spare time he is a contributor to Fedora Art, the Open Clip Art Library and a few other projects. Recently he grew an impressive beard and increased the darkness of the graphics he work on.

15 responses to “The open palette:How to use Inkscape’s new blur filter”

  1. andreu says:

    inkscape blur

  2. Richard "Ricardo" Szlachta says:

    Thanks a lot for great article. I am using opensource for two years and Inkscape from its 0.3someting version. I really didn’t understand what great thing blur is, but after reading your article, i was amazed. Again huge thanks to author for effort he put in this article. Keep going and good luck!

  3. Nicu Buculei says:

    Thanks Richard.
    Indeed, the blur filter is simply awesome and was one of the badly needed features, not only for artists but also for SVG compliance. It is the first, the most useful (and the only for now) filter implemented by Inkscape, but the SVG specs contain more other.

  4. Wassim says:

    As simple as that?! Wow!

  5. Zlatko Nikolic says:

    OK tutorial,thanks.

  6. Francesc Dorca says:

    Dear Nicu,

    First of all many thanks for your nice tutorial ;-)

    My name is Francesc Dorca and I am a member of Softcatalà a small and quite active non-profit Catalan software localisation group.

    Among many other programs (OOo, Mozilla Apps, GNOME, The GIMP…), we keep the Inkscape translation updated and have an Inkscape project page in our site.

    We also translated Inkscape’s Help tutorials as a tool for basic Inkscape use. I would like to translate and publish your tutorial in our website (www.softcatala.org) as a useful additional tutorial about the new blur feature.

    May I get your permission to do it?
    Best regards,

    Francesc

  7. Antonis K says:

    Dear Nicu,
    Thank you so much, for this amazing tutorial.

  8. shishira says:

    With just the Gaussian filter such amazing things can be done :)
    thanks for the tutorial

  9. VanHelsing.16 says:

    Thnx, really useful tutorial!

  10. dogsthatchasecars says:

    Thanks for a really cool tutorial, just what I was looking for, thank you again :))

  11. Federico Pedemonte says:

    Very nice tutorial! Thank you!

  12. RICHARD WHITE says:

    Thanks for the tutorial I don’t have an Apple but the article is so clearly set out I will have no problems using it on my PC.

  13. Nicu Buculei says:

    Richard, Inkscape runs primarily on PC, on both Linux and Windows. It has also a Mac version.
    The screenshots above are made on Linux (specifically, on Fedora).

  14. Red Hat Magazine - The Open Palette | Wallpapers gratis, Fondos Gratis says:

    [...] Red Hat Magazine started a series of of tutorials on how to create art with Free and Open Source creative tools. The first in the series, authored by me with help from Mairin is titled How to use Inkscape’s new blur filter and is a celebration (albeit a little late) of the 0.45 release of Inkscape. [...]

  15. TotalMedial » Blog Archiv » Inkscape 0.45 says:

    [...] Hier findet man ein Umfangreiches Tutorial (in englisch) zum Gebrauch des Inkscape Blur-Filters. Kategorie Allgemein, Grafik und Design, Software [...]